Electron discharge devices and circuit component stacked assembly



March 30, 1965 W. GRATTIDGE ELECTRCN DISCHARGE DEVICES AND CIRCUITCOMPONENT STACKED ASSEMBLY Original Filed Sept. 4. 1956 Wa/ferGraff/'dye by @iw/@fad H/s Afforney United States Patent O 4 Claims.(Cl. 315-59) The present invention relates tofan improved electricdischarge device and circuit component assembly and more particularly toan improved stacked assembly of this type adapted for high temperatureoperation. This application is a continuation of my copendingapplication Serial No. 607,732, tiled September 4, 1956, (now abandoned)and assigned to the assignee of this application.

There have been developeda number of applications for electric dischargedevices presenting stringent requirements with respect to one or lmoreof the following: high ambient temperature, vibration or shock, premiumon space, `and the ability to operate in a region subject to nuclearradiation. The same requirements apply to circuit components which arenecessarily associated with the electric discharge device so applied. Inaccordance with my invention, I provide a composite stacked structureproviding one or more discharge devices and at least a substantialportion of the circuit components employed therewith. More specifically,passive circuit elements such as circuit resistances, for example theanode or plateresistance and the grip-cathode or input resistance, areformed on inner surfaces of insulating parts of an evacuated envelope in:a manner which eliminates -a number of circuit `connections vandsubstantial external wire. The assembly is characterized by -a markedimprovement as compared with the prior art with respect to each of therequirements mentioned above.

It is an object of my invention `to provide a new and improved stackedassembly providing an electric discharge device and associated passivecircuit components.

It is another object of my invention to provide a new and improvedassembly providing an electric discharge device and one or more passivecircuit components in an evacuated envelope which is compact, rugged andoperable in high ambient temperatures.` Further objects and advantageswill become apparent as the following description proceeds, referencebeing had to the accompanying drawing `and its scope will be pointed outin the appended claims.

In the drawing, FIG; 1 is an elevational view in section of an electricdischarge device `and circuit component assembly embodying my'invention,FIG. 2 is a schematic wiring diagram of the circuit provided by theassembly of FIG. 1, FIG. 3 is an elevational view partially in sectionof a modified `form of'my invention, and FIG. 4 is a schematic wiring`diagram of the circuit provided by the assembly of FIG. 4.

Referring to FIG.,1 of the drawing, I have shown my invention embodiedin a stacked `assembly providing a [riode .type of electric dischargedevice, together with the formed within the device in such a manner thatthe circuit connections with the electrode are completed duringmanufacture of the device. The stacked assembly includes annularinsulating members -13, inclusive, and conducting terminal members14-18, inclusive, alternatively arranged and bonded together to provideVtive mutually inanode or plate resistor and grid-cathode resistor bothsulated terminals spaced by the insulators and forming a "icepatiblewith those of titanium. The bodies are of high purity and give ovvery little gas even when raised to a temperature of several hundreddegrees centigrade. The terminal members may be of any suitableconducting material and titanium or copper have been found particularlysuitable.

Within the envelope, the various electrodes of the device are supportedin spaced axial relation. The anode 19 may be formed integrally with theIanode terminal 15, the grid 20 supported by a grid ring held betweenthe upper surface of the insulator 12 and the grid terminal 16. Thecathode 21, as shown, is in the form of an inverted cup-shaped memberhaving the upper surface 22 thereof in closely spaced relation with theygrid 20. The cathode member 21 is coated on the upper surface thereofwith an electron emission enhancing material, such as one of thealkaline earthoxdes in accordance with a practice well understood in theart and is heated to emissive temperature by means of a resistanceheater 23 connected at one end to a central portion of the closed end ofthe cathode member 21'and at the other end to the heater-terminal 18.

In accordance with an important feature of rny invention, the inner wallof the insulator 12 surrounding the cathode 21 is provided with .acoating 24 which provides a film resistor connecting the grid supportingring and the cathode sleeve. In a similar manner, the insulator 10 isprovided with a resistance coating 25 on its inner surface which extendsbetween the conducting discs 14 and 15.`

These coatings are formed by 'applying to these surfaces a coating whichis reduced during the firing .and sealing of the envelope structure andits resistance is controlled by `the nature of this coating and theprocessing applied there- O.

While` the resistance coatings 24 and. 25 may be made by -a wide varietyof methods depending upon the resistance characteristics desired, thegrid cathode resistor 24 having a resistor from 1000 ohms to 100,000ohmsbut preferably in the order of 10,000 ohms may be formed toadvantage by the method described and claimed in Beggs Patent No.3,013,328, granted December 19, 1961, entitled Conducting Film. Inaccordance with one method there described, the sur-face of the ceramicon which the resistance film is to be formed, specifically the innerWall of the ceramic insulator 12, is painted with a mixture oflapproximately 30% iron and 70% titanium hydride by weight, in a binderincluding `a carbonaceous compound such as nitrocellulose. One of theadvantages of a coating of this type is that -it may be formed in placeduring the exhaustV and sealing of the stacked assembly, as will bedescribed 4in more` detail later in this specification.V It will also beunderstood that other materials and percentages of the composition maybe employed depending upon the magnitude of the resistance desired.

In many applications, it is desirable that the gridvcathode Vresistor beof substantially higher magnitude than readily obtainable by the methoddescribed above, and if a resistance in the order of .1 to megohms, forexample, is desired, the method described and claimed in Beggs andGrattidge Patent No. 2,961,352, granted November 22, 1960, may beemployed. In accordance with one embodiment of the invention theredescribed, the inner wall of the insulator 12 is coated with an oxidesuch as Fe203, TiO2 or ZrOz in a suitable organic binder such as vzaponand the coated insulator red. There also must be available during theprocessing of the coating a hydrogen-producing agent in order to reducethe oxide to'a desired extent and in this way control the resistance ofthelm. This wsupply of hydrogen may be provided readily by the presenceof titanium hydride, which is exposed to the interior of the device.Since a preferred manner of assembling the envelope of this stackeddevice includes the use of titanium hydride, this provides a reductionof the oxide. f

A betterv understanding of the present invention may bev had-byconsidering the manner inrwhichthe device of FIG. 1 may beVevacuateil.andlbonded together. For

purposes of Va specificV example, itiwill'rbe assumed. that fosterite'ceramics'having temperaturecoeicients of Vex-v the` necessary Vhydrogenfor f 'l Y are made Vinto aV unitaryvaligned assembly. Also, the'metalrterminal members are of smaller diameter than f the terminalmember'sf14f18, inclusivef-are of'titaniumV Yand that the insulatingmembers l-13,` inclusive, are

2,912,340, granted November10,'19 39 andiassigned to the assignee ofthis; application. Thegparts areassembled in the relationship showninFIG 1` andwspring loaded, i,e.

.the partsy are urged together in the stacked assembly shown in FIG.` lby theapplication of` spring pressure. Suitable shims'of a metal whichjacts as; a solderA are interposed between adjacent surfaces of theinsulating. members j-13 Vandfterminal members ,1 4-18, inclusive.Nickel isa suitable material for this shim. Also, inner walls` Yofinsulators 1 0 and 12are coatedwiththe constituents of the resistancefilm previouslydescribed. rThe assema ceramic'tube to` provideiiaresistance lm .25. VThis same temperatureisal's'o kadequate to 'eectthefforrfna- V,tionotthe resistancenlmon the inner wall of insulatorllt) by reducing the oxide coating and reacting kthe titanium, the metal'ofthe oxide andthe ceramic.V During this heating step also,the;titanium-nickelalloys and `bonds tothe ceramic members to sealthedevice. The junctions between adjacent insulating andfmetal members i Yeform passages *prior to the melting of the 'solder through v whichgases included'wi't'hin the envelope .mayy escape to .thevacuum-systemso .that'tby a single heating step,'the

entire device'is evacuated and bonded together.r

While, it ispossible to process part of the device sepik Aarately, fiorexample,.the'subassenibly including the metal 1 terminals 14- and"15 andinsulator 10 and resistancelni 25, for example, `couldbeiformed by aseparate heating Y the entire device, including both resistors, can beproduced in a-,single Operation; s Y .t 'In FIG. 2 they circuitrelationship'of `.the variousrele-v ments is illustrated schematically.These elements have been designated by` corresponding numerals in VvFIG. 1

, 'but have been primed todesignate theschematic. showand actually formsthe'element at which the two devices the insulating spacers.

i In addition tothe elements ofthe stacked assembly, the

" remainder of the circuit connectionsrequ-ired for the com- "shown inFIG. 4. The circuitelements corresponding to the upper and .lowerdischarge devices are designated in FIGf4byrnumberscorresponding'tothose used in FIG. 3.

As illustrated, 'the cathode terminals.:17 are. connected together andtoground as illustratedfat 26. The terminals 1d and 14 of the anoderesistors are connected together byconductor 27 and to a' source ofpositive direct voltage indicated as the B+ terminal. f The.anodeterminal 15' of the upper discharge device isvconnected through acapacitortZ tothegrid or input terminal 16 ofthe lower ydischargedevice. `In a similar mannen'the'anode terminal 15A of thejlowerdischarge deviceis connected with the control gridter'minal lof the:upper electric discharge device through a capacitor 29.Y fThe ontput'ofthe multivibrator circuit maylbe taken from the anode terminal 15;

. of the lowerz device throughcapacitortl.

The operation of the free-runningrnultivibra-tor 'circuit illustratedVin FIG. 4 and `Vembodied in thedevice as'illusr trated in FIG. 3iis notessential to the present invention, .since it isa conventional typeto'fVcircuit. it merely illus- @trates atype of-system ,which mayiberfpro'duced with a 30' stacked tube and' component assembly with aminimum Vof external circuit`connection(andtcomponents. i It will .beappreciated, howevenby those skillediin the art, that theconductivity'yof one of theftwo Velectric discharge devices increasesasvthe conductivity of the other decreases andv vice versa at a ratedependent upon the time constant of the circuits associated *withthefrcontrol grids. Y

@From-the foregoing detailed descritpion Vovf-tworembodii ments of myinvention, lt'willfbe.apparent'that thestacked `assemblies provide acombination ot'an electricdischarge devicejwith one or moreoftliei'ci'rcuit'fresistors'commonly employed with .thejdevices,` all ina structure which ik may be manufactured ir--a single assembly andexhaust step, AitisV an advantage VYof the.` present` lnventlon that Yopera-tion andthe resul-ting product of'which Vis lsuitable 'foroperation at'high'temperatures, for example, temperatures exceeding 500`C. and in environments which are 1 subjectedto radiation.

. While I have described particular embodiments of my invention, Vitwill apparent to those skilled in the art that ing. i It is. clear thatthe assembly ofFIG. 1 provides lthe charge device, the grid-cathoderesistor 24 and the anodecathode resistor 25 all produc/ed in aV unitarydevice in a Y VIt will be apparent to those'skilled in the v-artthat'the ployedk to the production of'otherfcircuit arrangements 'basic'circuitk combination including atriode electric dis-V` Y conceptinvolved inthe present` invention maygbe ernt of my invention.

changes andY modifications may be. 'rnade without departingfrommyinvention in its 'broader aspects and I aim, therefore, in the appendedclairns to cover VallY such changes and modifications as Vfall withinthe .true `spirit and scope What I claim as Ynew and desire yto secureby `Letters Patentofthe United Statesis; x n l f n 1. Anelectric'discharge device'irl'cuit assembly'comprising'a stackvofdisc-like vrnetal'terminalY members and n a Vplurality of hollowcylindrical Vinsulating members disposedV respectively between pairs 'ofsaid terminal members and 1 cooperating therewith to provideV anenvelopestructure, electric discharge device electrodes-Within saidV Venvelopestructure connected respectively with diiferent by meansof a stackedassembly. suitably Vchosen Vto produce Y.

the circuitelements desired.V As oneV furtherfexampleV of afui'therembodiment of my invention,rl-.have illustrated inV FIG.kv 3 a pair; ofelectric discharge devices arranged reference numerals AprimedhaveY beenapplied to corresponding partsof the upper discharge device whilecorresponding parts of the lower Vdischargedevice are cles-Y vignated bydoubly primed-reference numerals.V Ylt will be appreciated thattheheater terminal 18 isnot duplicated ones of said terminals to provideaV plurality of electric discharge devices each including an anode,a-control member, anda cathode in spacedrelation longitudinally of saidstack and passive circuit elements within said envelope structureeach:electricallyconnectedl between a terminal Vto which` onefofsaidfanordes is connectediand'a terminal spaced therefrom in said stack`in the direction lremote lfrom the correspondingcontrol member terminalto Vprovide a plurality of electric Ydischarge paths each having inseries therewith one of said passive'. circuit elements andv meanscoupling the anode-cathodejcircuit 4of one of said discharge devices inaccordance with the discharge in the rst of said devices.

2. An electric discharge device circuit assembly comprising a stack ofdisc-like metal terminal members and a plurality of hollow cylindricalinsulating members disposed respectively between pairs of said terminalmembers and cooperating therewith to provide an envelope structure,electric discharge device electrodes within said envelope structureconnected respectively with different ones of said terminals to providea plurality of electric discharge deivces each including an anode and acathode in spaced relation longitudinally of said stack and passivecircuit elements within said envelope structure each electricallyconnected between a terminal to which one of said anodes is connectedand a terminal spaced therefrom in said stack in lthe direction remotefrom the corresponding cathode terminal to provide a plurality ofelectric discharge paths each having in series therewith one of saidpassive circuit elements and means coupling the anodecathode circuit ofone of said discharge devices to a terminal of a second of saiddischarge devices to control the discharge in the second of saiddischarge devices in accordance with the discharge in the irst of saiddevices.

3. An electric discharge device circuit assembly cornprising a stack ofdisc-like metal terminal members and a plurality of hollow cylindricalinsulating membersdisposed respectively between pairs of said terminalmembers and Icooperating therewith to provide an envelope structureelectric discharge device electrodes within said envelope structureconnected respectively with different ones of said terminals to providea plurality of electric discharge devices each including an anode, acontrol member, and a cathode in spaced relation longitudinally of saidstack and lm resistor elements each on an inner wall of one of saidinsulating members and each electrically connected between a terminal towhich one of said anodes is connected and a terminal spaced therefrom insaid stack in the direction remote from the corresponding control memberterminal to provide a plurality of electric discharge paths each havingin series therewith 2,771,566 ll/56 Bracket 313-82 X` one of said filmresistor elements and means coupling the anode-cathode circuit of one ofsaid discharge devices to the control member of a second of said devicesto control the discharge in the second of said discharge devices inaccordance with the discharge in the iirst of said devices.

4. An electric discharge device circuit assembly comprising a stack ofdisc-like metal terminal members and a plurality of hollow cylindricalinsulating members disposed respectively between pairs of said terminalmembers and cooperating therewith to provide an envelope structure,electric discharge device electrodes within said envelope structureconnected respectively with different ones of said terminals to providea plurality of electric discharge devices each including an anode, acontrol member, and a cathode in spaced relation longitudinally of saidstack and passive circuit elements within said envelope structure eachelectrically connected between a terminal to which one of said anodes isconnected and a terminal spaced therefrom in said stack in the directionremote from the corresponding control member terminal to provide aplurality of electric discharge paths each having in series therewith apassive circuit element, a resistance iirn on the inner Wall of theinsulating member between the terminal members to which the controlmember and cathode of each of said discharge devices to provide withinsaid envelope control member-cathode resistors for said dischargedevices, and means coupling v the anode-cathode circuit of one of saiddischarge devices to the control member of a second of said devices tocontrol the discharge in the second of said discharge devices inaccordance with the discharge in the first of said devices.

References Cited by the Examiner UNITED STATES PATENTS 6/53 DiemerS13-293 X 2,910,607 10/59 McCullough et al. 313-257 X GEORGE N. WESTBY,Primary Examiner.

1. AN ELECTRIC DISCHARGE DEVICE CIRCUIT ASSEMBLY COMPRISING A STACK OFDISC-LIKE METAL TERMINAL MEMBERS AND A PLURALITY OF HOLLOW CYLINDRICALINSULATING MEMBERS DISPOSED RESPECTIVELY BETWEEN PAIRS OF SAID TERMINALMEMBERS AND COOPERATING THEREWITH TO PROVIDE AN ENVELOPE STRUCTURE,ELECTRIC DISCHARGE DEVICE ELECTRODES WITHIN SAID ENVELOPE STRUCTURECONNECTED REPSECTIVELY WITH DIFFERENT ONE OF SAID TERMINALS TO PROVIDE APLURALITY OF ELECTRIC DISCHARGE DEVICES EACH INCLUDING AN ANODE, ACONTROL MEMBER, AND A CATHODE IN SPACED RELATION LONGITUDINALLY OF SAIDSTACK AND PASSIVE CIRCUIT ELEMENTS WITHIN SAID ENVELOPE STRUCTURE EACHELECTRICALLY CONNECTED BETWEEN A TERMINAL TO WHICH ONE OF SAID ANODES ISCONNECTED AND A TERMINAL SPACED THEREFROM IN SAID STACK IN THE DIRECTIONREMOTE FROM THE CORRESPONDING CONTROL MEMBER TERMINAL TO PROVIDE APLURALITY OF ELECTRIC DISCHARGE PATHS EACH HAVING IN SERIES THEREWITHONE OF SAID PASSIVE CIRCUIT ELEMENTS AND MEANS COUPLING THEANODE-CATHODE CIRCUIT OF ONE OF SAID DISCHARGE DEVICES TO THE CONTROLMEMBER OF A SECOND OF SAID DEVICES TO CONTROL THE DISCHARGE IN THESECOND OF SAID DISCHARGE DEVICES IN ACCORDANCE WITH THE DISCHARGE IN THEFIRST OF SAID DEVICES.